EFFECT OF NITRIC OXIDE, VITAMIN E AND SELENIUM ON STREPTOZOTOCIN INDUCED DIABETIC RATS

Diabetes mellitus is characterized by a serious of complications that affect many organs. Aim: This study aimed to investigate the role of nitric oxide (NO) as a physiological mediator in the body via the use of L-arginine as NO precursor and NG-nitro-L-arginine methyl ester (L- NAME) as Nitric oxide synthase (NOS) enzyme inhibitor in diabetic rats. The effect of vitamin E as antioxidant and selenium as a potent insulin-mimetic agent in diabetic rats were studied. Methods: The possible combination of selenium or vitamin E with L-arginine was studied in the same animal model to show the ability of these treatments to ameliorate some of the biochemical changes that are worsen with the development of diabetes such as lipid profile, plasma glucose, blood malondialdehyde (MDA), plasma nitric oxide plasma â2- microglobulin levels. Experimental diabetes was induced in male rats by I.V. injection of Streptozotocin (STZ) (50 mg/kg). Results: Diabetic rats showed a significant increase (P 0.05) in plasma level of glucose, triglycerides, total cholesterol, LDL-cholesterol, â2 – micro globulin, blood MDA as a result of increased oxidative stress while there was a significant decrease in plasma HDL- cholesterol, and nitrate/nitrite levels. L-arginine, vitamin E and selenium administration produced a significant decrease in plasma glucose level of diabetic rats (13%,29.11%,61.65%) respectively from its initial value, also they showed a significant reduction in blood MDA level, plasma triglyceride, total cholesterol, LDL-Ch. and â2-microglobulin levels but showed a significant increase in plasma nitrate/nitrite and HDL-Ch.. levels when compared with the initial diabetic values. Combined therapy of vitamin E and L-arginine showed no significant change of any of the measured parameters ( except for nitrate/nitrite level) on comparison either with vitamin E or with L-arginine treated group. Conclusion: The combined therapy of selenium L-arginie showed a significant decrease nearly to normal level in the plasma glucose concentration may be of clinical signifiance.